Bug 552092 - Expose a length property on mozIStorageBindingParamsArray

Expose the length so that consumers don't have to track if they added anything
to the array themselves.
r=asuth
sr=rob_strong

storage/public/mozIStorageBindingParamsArray.idl

@@ -41,14 +41,14 @@
 
 interface mozIStorageBindingParams;
 
-[scriptable, uuid(e676e1a3-1dc6-4802-ac03-291fa9de7f93)]
+[scriptable, uuid(67eea5c3-4881-41ff-b0fe-09f2356aeadb)]
 interface mozIStorageBindingParamsArray : nsISupports {
   /**
    * Creates a new mozIStorageBindingParams object that can be added to this
    * array.
    *
-   * @returns a mozIStorageBindingParams object that can be used to specify
-   *          parameters that need to be bound.
+   * @return a mozIStorageBindingParams object that can be used to specify
+   *         parameters that need to be bound.
    */
   mozIStorageBindingParams newBindingParams();
 
@@ -59,4 +59,9 @@ interface mozIStorageBindingParamsArray : nsISupports {
    *        The parameters to add to this array.
    */
   void addParams(in mozIStorageBindingParams aParameters);
+
+  /**
+   * The number of mozIStorageBindingParams this object contains.
+   */
+  readonly attribute unsigned long length;
 };

storage/src/mozStorageBindingParamsArray.cpp

@@ -109,5 +109,12 @@ BindingParamsArray::AddParams(mozIStorageBindingParams *aParameters)
   return NS_OK;
 }
 
+NS_IMETHODIMP
+BindingParamsArray::GetLength(PRUint32 *_length)
+{
+  *_length = length();
+  return NS_OK;
+}
+
 } // namespace storage
 } // namespace mozilla

storage/test/unit/test_statement_executeAsync.js

@@ -520,6 +520,7 @@ function test_bind_multiple_rows_by_index()
     bp.bindByIndex(3, null);
     bp.bindBlobByIndex(4, BLOB, BLOB.length);
     array.addParams(bp);
+    do_check_eq(array.length, i + 1);
   }
   stmt.bindParameters(array);
 
@@ -589,6 +590,7 @@ function test_bind_multiple_rows_by_name()
     bp.bindByName("null", null);
     bp.bindBlobByName("blob", BLOB, BLOB.length);
     array.addParams(bp);
+    do_check_eq(array.length, i + 1);
   }
   stmt.bindParameters(array);